The transmission in my 94 4.9l F150 has been giving me a few problems. From the sitting, parked, position it would take about 10-30 seconds to go into gear (reverse or drive). About a week ago while driving home, the speedometer suddenly stopped working. Now I'm experiencing hard shifts along with the previous problems. I changed the vehicle speed sensor on the rear end and the PSOM with a second-hand one. No change. The speedometer still doesn't work along with the odometer but it does light up. No visible problems with the wiring. Any suggestions before I take it the tranny shop and fork out big bucks? Would a new tranny fix my speedometer issue? Thanks in advance.

 

Check Fuse 18. That powers the PSOM when the key is in the Run position. With that fuse open the PSOM is useless therefore the computer has no valid vehicle speed input which puts the computer (PCM) in limp mode. Hard/delayed shifts are the symptom.

 

That was one of the problems!. I previously checked the number 8 fuse, but not the number 18. Now it keeps blowing the 10 amp fuse for the number 18, so I put a 15 amp in there temporarily to see if that was the hard shift/speedometer culprit, and it was. Any ideas why it may be blowing the 10a? Is there any usual areas of wear on the wires in that area?

Thanks again!

 

Went fishin' one time and must have upset the fellas parked next to me. They got in my truck and yanked a bunch of fuses and I had the same symptoms.